U.S. patent number 11,278,926 [Application Number 16/722,227] was granted by the patent office on 2022-03-22 for pipeline sprayer and method.
This patent grant is currently assigned to CRC-Evans Pipeline International, Inc.. The grantee listed for this patent is CRC-EVANS PIPELINE INTERNATIONAL, INC.. Invention is credited to Garrett Barlett, Timothy Bond, Michael George, Siddharth Mallick.
United States Patent |
11,278,926 |
George , et al. |
March 22, 2022 |
Pipeline sprayer and method
Abstract
Provided is an apparatus for coating a girth weld and a cutback
region surrounding said girth weld, said apparatus having lateral
travel at least equal to the length of the cutback region and
circumferential rotational travel around the pipe. The apparatus
can provide a multiple component coating accurately and safely,
without the need for solvent flushing of the apparatus.
Inventors: |
George; Michael (Tomball,
TX), Barlett; Garrett (Claremore, OK), Bond; Timothy
(Cypress, TX), Mallick; Siddharth (Spring, TX) |
Applicant: |
Name |
City |
State |
Country |
Type |
CRC-EVANS PIPELINE INTERNATIONAL, INC. |
Houston |
TX |
US |
|
|
Assignee: |
CRC-Evans Pipeline International,
Inc. (Houston, TX)
|
Family
ID: |
1000006191381 |
Appl.
No.: |
16/722,227 |
Filed: |
December 20, 2019 |
Prior Publication Data
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|
|
Document
Identifier |
Publication Date |
|
US 20210187534 A1 |
Jun 24, 2021 |
|
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
B05B
13/0426 (20130101); B05C 5/0241 (20130101); B05B
12/087 (20130101); B05C 5/0216 (20130101); B05C
5/0208 (20130101); B05B 13/0436 (20130101); B05B
12/084 (20130101); B05C 5/02 (20130101); B05B
13/0431 (20130101); B05B 7/26 (20130101); B05D
2254/02 (20130101) |
Current International
Class: |
B05B
13/04 (20060101); B05B 12/08 (20060101); B05C
5/02 (20060101); B05B 7/26 (20060101) |
References Cited
[Referenced By]
U.S. Patent Documents
Foreign Patent Documents
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3059482 |
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Jul 2018 |
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EP |
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0132316 |
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May 2001 |
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WO |
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2011162747 |
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Dec 2011 |
|
WO |
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Other References
Extended European Search Report dated May 21, 2021. cited by
applicant.
|
Primary Examiner: Pence; Jethro M.
Attorney, Agent or Firm: Schulterbrandt; Kofi A.
Claims
What is claimed is:
1. A sprayer for coating a girth weld and a cutback region
surrounding said girth weld on a steel pipe, the steel pipe
including a longitudinal axis, the sprayer comprising: a track
affixed around the steel pipe proximal longitudinally to said
cutback region and affixed circumferentially around said steel
pipe, a frame including a roller carriage configured for rollably
mounting to the track, said frame further including a powered
propulsion assembly for propelling said roller carriage
circumferentially around said track; said sprayer including an arm,
said arm cantilevered longitudinally from said roller carriage;
said arm including a spray head extending therefrom; said frame
also including a powered indexing assembly for moving said arm and
said spray head longitudinally relative to said roller carriage;
the frame further including a cartridge for storing a liquid to be
sprayed onto the steel pipe via the spray head; the frame also
including a powered cartridge gun for forcing the liquid out of the
cartridge to the spray head; the frame further including a
pressurized air supply for delivering pressurized air to the spray
head to control a pattern of the liquid as said liquid is sprayed
from said spray head; a controller, the controller controlling the
powered propulsion assembly, the powered indexing assembly, and one
of the powered cartridge gun and a pressure level from the
pressurized air supply to the spray head to respectively vary a
flow rate of the liquid supplied to the spray head or vary a spray
pattern, wherein the control of the powered cartridge gun or the
pressurized air supply depends on a longitudinal position of the
spray head.
2. The sprayer of claim 1, wherein the controller controls both the
powered cartridge gun and the pressure level from the pressurized
air supply to the spray head.
3. The sprayer of claim 1, wherein control of the powered
propulsion assembly, the powered indexing assembly, and one of the
powered cartridge gun and the pressure level from the pressurized
air supply to the spray head depends upon a longitudinal indexed
position of the spray head along the cutback region.
4. The sprayer of claim 2, wherein the controller directs the
powered cartridge gun to vary a flow rate of the liquid supplied to
the spray head.
5. The sprayer of claim 4, where a variation in the flow rate is
dependent on the longitudinal position of the spray head along the
cutback region.
6. The sprayer of claim 2, wherein the controller directs the
pressurized air supply to vary a pressure of air supplied to the
spray head.
7. The sprayer of claim 6, wherein a variation in flow rate is
dependent of the longitudinal position of the spray head along the
cutback region.
8. The sprayer of claim 2, wherein the controller directs the
powered cartridge gun to vary a flow rate and directs the
pressurized air supply to vary an air pressure supplied to the
spray head.
9. The sprayer of claim 2, wherein the controller sets a thickness
of an applied spray material by directing the powered cartridge gun
to vary a flow rate, directing the pressurized air supply to vary
an air pressure supplied to the spray head, and by directing one of
the powered propulsion assembly and the powered indexing assembly
to control a speed of the spray head.
10. The sprayer of claim 1, wherein the controller directs the
powered indexing assembly to indexingly adjust the spray head into
multiple longitudinal positions along the cutback region so that
adjacent index positions produce spray patterns that overlap.
11. The sprayer of claim 1, wherein the spray head includes a spray
nozzle and wherein the spray nozzle is pivotable relative to the
arm.
12. The sprayer of claim 1, wherein the sprayer further includes a
material supply hose for supplying spray material to a spray nozzle
of the spray head and wherein at least a portion of the material
supply hose at the connection between the material spray hose and
the spray nozzle guides spray material parallel to a longitudinal
axis of the spray nozzle.
Description
BACKGROUND OF THE INVENTION
The present invention relates to an apparatus for coating pipes,
particularly, to coating the exposed steel weld joint cutback area
on oil and gas pipeline as it is being built.
Typically, oil and gas pipelines are formed from many lengths
(typically 20, 40, or 60 feet) of steel pipe, attached by girth
weld, end to end. The steel pipe lengths are coated, typically with
a polyolefin coating, or a multi-layer coating comprising for
example an epoxy first coat followed by a polyethylene or
polypropylene top coat. This coating has multiple purposes,
imparting corrosion and impact resistance to the pipe. Typically,
the pipe lengths have an exposed region at each end of the pipe,
where the steel is exposed and not coated. This exposed region is
usually between 4 and 18 inches in length, and exists to facilitate
girth welding the pipe end to the pipeline. When a pipe length is
added to a pipeline, the exposed metal end is girth welded to the
end of the pipeline (which is also exposed metal), producing a
girth weld area with an adjacent uncoated region of pipe (the
"cutback region"). This cutback region must be coated to prevent
corrosion and provide impact resistance.
There are many competing technologies for coating the cutback
region. One technology is to apply a shrink sleeve or wrap to the
area. The shrink sleeve or wrap can be one, two, or multi-ply, but
is often a two-ply structure comprising an adhesive layer applied
to the pipe, and an external polyolefin layer. The sleeve or wrap
can be heat shrunk to the cutback region using an exposed flame
torch, or by using heating elements applied around the sleeve or
wrap. Often, the exposed steel cutback region is epoxy coated,
typically with a 150-300 micron primer epoxy layer, before the
sleeve or wrap is applied.
Another technology for coating the cutback region is a one layer,
stand alone, high-build epoxy coating, typically 500-1500 microns
in thickness.
For both of the abovementioned, the coating is typically applied by
mixing a two-part liquid mixture, typically a two-part polyurethane
or epoxy coating supplied as two liquids which set chemically when
mixed together, then applying it to a hot metal pipe manually, with
a roller, brush, sponge or the like. Although this is a relatively
inexpensive and simple way of applying the coating, it introduces
user error, inconsistency in application thickness, and significant
health and safety concerns due to the toxicity of the liquid
coating and the intense heat of the pipe. It is difficult for a
user to apply an even coating all around the surface of a pipe,
especially when under the rigid time constraints applied when
installing pipeline. Thus, the top and sides often receive a
thicker layer of coating than the underside, which is
undesirable.
Alternative, automated systems are known, for example, a
high-pressure plural component spray unit such as the HydraCat.TM.
fixed ratio mechanical proportioner (Graco, Minneapolis, Minn.,
USA) can be utilized to mix the two liquid components of the epoxy
mixture, and simultaneously spray the mixture onto the field joint
area. However, such hand-held spray units do not resolve the issues
of user error, inconsistency in application thickness (such as
overspray proximal to the user and/or underspraying in hard to
reach areas), and often even greater health and safety concerns due
to the airborne epoxy spray.
Automated spray systems have been developed.
U.S. Pat. No. 5,207,833, incorporated by reference, discloses a
machine which can travel down a pipe applying a protective coating.
The machine has a two-piece yoke which is fitted around the pipe,
with each piece serving as a track on which a spray gun moves. The
machine is not well suited for coating cut back regions at a girth
weld, and has other significant disadvantages, including a
requirement for flushing the spray apparatus with solvent between
each use.
PCT patent publication WO01/32316A1, incorporated herein by
reference, discloses a body for mounting on a pipe to be coated,
with a spray gun mounted thereto. The spray gun is configured to
rotate around the body to spray coating completely around the
periphery of the pipe. The spray gun travels a full 360 degrees
around the periphery of the pipe. The spray gun can be adapted for
spraying a two-part coating, by having a mixing block in which the
at least two parts are combined before being fed to the spray gun.
Tubing is required between the mixing block and the gun, and the
mixed coating in the mixing block and gun must be flushed after
each coating operation utilizing a flushing solvent, which can be
undesirable. The method disclosed includes clamping the body onto
the pipe after mounting, directing the spray gun away from the
pipe, turning the pipe nozzle to a jet position, flushing the spray
gun with solvent, priming the spray gun with coating, stopping the
flow of coating, turning the nozzle tip to a spray position, and
turning the spray gun towards the pipe, before causing the spray
gun to spray coating at the pipe. After coating the pipe, the spray
gun must be flushed again to remove mixed coating. These numerous
steps for the priming and pre-flushing of the spray gun before and
after use are generally undesirable due to their complexity, their
time requirements, and due to the use of undesirable solvents. In
addition, the apparatus requires long and elaborate connection
tubes (coating and solvent lines) running 50-100 feet from a main
spray dosing unit to the application spray tip, to deliver coating
and flushing solvent, since the coating and solvent reservoirs are
not integrated with the spray gun, and hence do not rotate with it
around the pipe. There are at least 3 lines (each part of the
two-part coating having its own line, and the solvent line) but may
be as many as 5 lines (recirculation hoses) which become wrapped
and unwrapped as the spray gun rotates around the pipe. Typically,
this requires 1-2 additional operators just to manage the line
travel. It also limits the number of times the spray gun can rotate
around the pipe--typically the rotation is limited to 360 degrees.
The lines, and the dosing unit, operate at high pressure, often at
least 1000 psi and higher, generally operated at 4000 psi delivered
at the outlet of the pump, and with system operating maximum
capabilities as high as 7250 psi, requiring large and cumbersome
pressurization equipment to pressurize the large dosing unit
containers of coating and the coating lines. The apparatus also
requires an elaborate waste management system of receptacles,
baffles and drains, mostly to manage the toxic solvent, and
requires high pressure fluid due to the needs of the spray gun and
the length of the lines, along with accompanying and multiple
pressure regulators and valves. The apparatus that is affixed to
the pipe is large, heavy, and unwieldy, and attaches to both ends
of the cutback region--thus the apparatus must be designed and
fabricated to be as wide as at least the largest cutback region it
is designed to coat, plus portions on each end for affixing the
apparatus to the pipe. Because, as discussed above, the exposed
region is usually between 4 and 18 inches in length, the apparatus
is typically over 24 inches in length and includes two portions,
one on each side, that clamp to the pipe, resulting in a large and
awkward device that is typically hoisted into place.
PCT patent publication WO 2011/162747, incorporated herein by
reference, also discloses a plural component coating application
system. The publication improves upon the previous systems by doing
away with the toxic solvent priming and cleaning steps, using a
high-pressure inert gas for priming and purging the spray gun and
lines. Although the system removes the need for the undesirable
solvent, it still has many of the disadvantages of the previous
systems, including long, unwieldy lines for feeding the two-part
coating to the spray gun, which is exasperated by the complex and
unwieldy high pressure gas delivery system and its accompanying and
multiple pressure regulators and valves. The system also clamps to
pipe regions surrounding both ends of the cutback region, resulting
in a device that is typically over 24 inches in length, and which
must typically be hoisted into place.
U.S. Pat. No. 8,844,463, incorporated herein by reference, also
describes a coating application system.
Hand-held, low pressure spray apparatus are also known, but rely on
user skill to provide an even, complete coating of the pipe.
It would be desirable to have a relatively small, simple, solvent
free, automated spray apparatus system for uniformly coating a
cut-back area around a girth weld with a plural component
coating.
SUMMARY OF THE INVENTION
According to one aspect of the invention is provided an apparatus
for coating a girth weld and a cutback region surrounding said
girth weld on a coated steel pipe, comprising: a frame having: a
roller carriage configured for mounting to a track affixed proximal
to said cutback region and circumferentially around said coated
steel pipe, said roller carriage having powered circumferential
travel means providing circumferential rotational travel of said
support frame at least 350, preferably 360, most preferably
infinitely, around said track; and an arm cantilevered laterally
from said frame; said arm having a spray head region at an end of
said arm distal to said frame; said arm having powered lateral
travel means providing lateral travel of the spray head region
relative to said frame, the distance of said lateral travel at
least equal to the length of half of the cutback region;
controllable means for spraying a mixed, multi-component liquid
coating from the spray head region onto the cutback region to be
coated; and a controller operatively linked to and controlling the
powered lateral travel means, the powered circumferential travel
means, and the means for spraying the mixed, multi-component liquid
coating.
In certain embodiments, the powered circumferential travel means
comprises a powered drive gear on the support frame, operatively
connected to and displacing along a rack on the track.
In certain embodiments, the powered circumferential travel means
also comprises an electric motor for powering the powered drive
gear.
In certain embodiments, the powered drive gear is pneumatically
powered.
In certain embodiments, the powered drive gear is hydraulically
powered.
In certain embodiments, the controllable means for spraying a
mixed, multi-component liquid coating from the spray head region
onto the cutback region to be coated comprises: a cartridge
carriage configured to receive at least one cartridge and
optionally two or more than two cartridges, each said cartridge or
cartridges containing one of the components of the multi-component
liquid coating, or optionally more than one component of the
multi-component liquid coating in separate compartments, wherein,
when in use, the cartridge carriage contains at least one cartridge
and at least two components of the multi-component liquid coating
housed within said at least one cartridge; displacement means for
displacing the at least two components of the multi-component
liquid coating out of the cartridge or cartridges and into a mixer
which mixes the at least two components to form the multi-component
liquid coating, and therefrom through a spray nozzle attached,
optionally by a multi-component liquid coating component hose, to
said mixer; said spray nozzle affixed to the spray head region and
configured to spray the multi-component liquid coating onto the
cutback region when the apparatus is mounted to a track affixed
proximal to said cutback region.
In certain embodiments, the cartridge or cartridges, the mixer,
and/or the spray nozzle are disposable consumables.
In certain embodiments, the cartridge or cartridges may be
refillable, for example, they may be continuously filled, from a
low-pressure bulk supply of component.
In certain embodiments, the cartridge or cartridges, the mixer,
and/or the spray nozzle are reusable. In certain embodiments, for
example, where the cartridge or cartridges are refillable and
re-usable, the mixer and/or the spray nozzle can be disposable
consumables, which, in certain embodiments, allows the use of a low
pressure bulk supply of component without the need for
solvent-based cleaning of the system (since all components
downstream of the mixing of the multi-component liquid are
disposable).
In certain embodiments, the apparatus further comprises the spray
nozzle.
In certain embodiments, the spray nozzle comprises a pressurized
air input.
In certain embodiments, the apparatus further comprises a power
source for the powered lateral travel means, the powered
circumferential travel means, and/or the means for spraying the
mixed, multi-component liquid coating.
In certain embodiments, the displacement means for displacing the
at least two components is controlled by the controller.
In certain embodiments, the displacement means for displacing the
at least two components comprises a piston for displacement of each
of the components out of the cartridge or cartridges, and a
cartridge gun for displacing the pistons.
In certain embodiments, the cartridge gun is selected from a
pneumatic cartridge gun, an electric cartridge gun, and a hydraulic
cartridge gun.
In certain embodiments, the arm comprises at least two, preferably
three, shafts, linking the spray head region with the frame, and
slidable relative to the frame.
In certain embodiments, the powered lateral travel means is a
non-captive stepper motor on said frame, turning a lead screw on
said arm, which in turn moves the arm relative to the frame.
In certain embodiments, the spray head region is laterally and/or
transversely adjustable relative to the arm and frame.
In certain embodiments, the apparatus further comprises a control
box wired to the controller, said control box having a user
interface for operating and/or programming the apparatus.
In certain embodiments, the two components of the multi-component
liquid coating comprise (a) an epoxy base and (b) an epoxy curing
agent.
In certain embodiments, the cartridges are of an appropriate size
to contain sufficient epoxy curing agent and/or epoxy base,
respectively, for coating one cutback region.
In certain embodiments, the apparatus further comprises heating
means for heating the cartridges, said heating means configured to
travel with said reservoir frame.
In certain embodiments, the apparatus further comprises: at least
two continuous component inlets each adapted to receive a high
pressure line through which a component flows; a valve for
controlling the flow of component from the component inlets into a
mixer which mixes the components to form the multi-component liquid
coating, and therefrom through a spray nozzle attached, optionally
through a high pressure multi-component liquid coating hose, to
said mixer; said spray nozzle affixed to the spray head region and
configured to spray the multi-component liquid coating onto the
cutback region when the apparatus is mounted to a track affixed
proximal to said cutback region.
In certain embodiments, the apparatus further comprises: at least
two continuous component inlets each adapted to receive a low
pressure line through which a component flows; a valve for
controlling the flow of component from each of the component inlets
into an on-board reservoir, a mixer which mixes the components to
form the multi-component liquid coating, and therefrom through a
spray nozzle attached, optionally through a low pressure
multi-component liquid coating hose, to said mixer; said spray
nozzle affixed to the spray head region and configured to spray the
multi-component liquid coating onto the cutback region when the
apparatus is mounted to a track affixed proximal to said cutback
region.
In certain embodiments, the apparatus further comprises the mixer,
the high- or low-pressure multi-component liquid coating hose,
and/or the spray nozzle.
In certain embodiments, the nozzle, the high- or low-pressure
multi-component liquid coating hose, and/or the spray nozzle, are
disposable consumables.
In certain embodiments, the nozzle, the high- or low-pressure
multiple component liquid coating hose, and/or the spray nozzle are
reusable.
In certain embodiments, only the nozzle and the mixer are
disposable consumables.
In certain embodiments, the powered circumferential travel means
provides variable, user selectable rotation speed.
In certain embodiments, the circumferential travel means provides
unidirectional travel.
In certain embodiments, the circumferential travel means provides
bidirectional travel.
In certain embodiments, the apparatus further comprises a plurality
of wheels affixed to the roller carriage to facilitate
circumferential travel of said frame around said pipe.
According to a further aspect of the invention is provided a method
of coating a cutback region of a pipe, comprising: (a) affixing or
clamping a track having a rack, circumferentially around an outer
surface coating of said pipe, proximal to said cutback region; (b)
mounting an apparatus as herein described to said track so that the
circumferential travel means engages with the rack; (c) positioning
the spray head region laterally within the cutback region of the
pipe; (d) installing the at least one cartridge into the cartridge
carriage, said at least once cartridge loaded with at least two of
the components of the multi-component liquid coating; (e) priming
the mixer and spray nozzle with multi-component liquid coating by
displacing the components from the cartridge into the mixer and
spray nozzle; (f) spraying the multi-component liquid coating out
of the spray nozzle onto the cutback region of the pipe while
rotating the apparatus around the pipe; (g) optionally displacing
the spray head region laterally relative to the frame of the
apparatus, while rotating the apparatus around the pipe or between
rotation cycles, to spray the multi-component liquid coating onto
the entirety of the cutback region, resulting in a relatively even
coating of the multi-component liquid coating onto cutback region;
wherein step (d) is done in any order relative to the other steps,
and steps (a), (b), (c), (e) and (f) are done in the order herein
provided.
In certain embodiments, the at least one cartridge is pre-heated
before installation.
In certain embodiments the multi component liquid delivery flow
rate is measured continuously during operation.
In certain embodiments, the method also includes providing
pressurized air to the nozzle during the spraying step.
In certain embodiments, steps (e) and optionally (f) are computer
controlled and automated.
According to a further aspect of the present invention is provided
a method of coating a cutback region of a pipe, comprising: (a)
affixing or clamping a track having a rack, circumferentially
around an outer surface coating of said pipe, proximal to said
cutback region; (b) mounting an apparatus as herein described to
said track so that the circumferential travel means engages with
the rack; (c) positioning the spray head region laterally within
the cutback region of the pipe; (d) installing the high pressure
component lines to the continuous component inlets; (e) priming the
mixer and spray nozzle with multi-component liquid coating by
displacing the components from the high pressure component lines
into the mixer and spray nozzle; (f) spraying the multi-component
liquid coating out of the spray nozzle onto the cutback region of
the pipe while rotating the apparatus around the pipe; (g)
optionally displacing the spray head region laterally relative to
the frame of the apparatus, while rotating the apparatus around the
pipe or between rotation cycles, to spray the multi-component
liquid coating onto the entirety of the cutback region, resulting
in a relatively even coating of the multi-component liquid coating
onto cutback region; wherein step (d) is done in any order relative
to the other steps, and steps (a), (b), (c), (e) and (f) are done
in the order herein provided.
According to a further aspect of the present invention is provided
a method of coating a cutback region of a pipe, comprising: (a)
affixing or clamping a track having a rack, circumferentially
around an outer surface coating of said pipe, proximal to said
cutback region; (b) mounting an apparatus as herein described to
said track so that the circumferential travel means engages with
the rack; (c) positioning the spray head region laterally within
the cutback region of the pipe; (d) installing the low pressure
component lines to the continuous component inlets; (e) filling an
on-board reservoir for each of the components with component from
the low pressure component lines; (f) priming the mixer and spray
nozzle with multi-component liquid coating by displacing the
components from the on-board reservoirs into the mixer and spray
nozzle; (f) spraying the multi-component liquid coating out of the
spray nozzle onto the cutback region of the pipe while rotating the
apparatus around the pipe; (g) optionally displacing the spray head
region laterally relative to the frame of the apparatus, while
rotating the apparatus around the pipe or between rotation cycles,
to spray the multi-component liquid coating onto the entirety of
the cutback region, resulting in a relatively even coating of the
multi-component liquid coating onto cutback region; wherein steps
(d) and (e) are done in any order relative to the other steps, for
example, step (e) being done continuously; and steps (a), (b), (c)
and (f) are done in the order herein provided.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a front perspective view of an apparatus according to the
prior art, affixed to a pipe at a girth weld.
FIG. 2 is a rear perspective view of the apparatus of FIG. 1.
FIG. 3 is an enlarged view of the region of FIG. 2 depicted with a
"B".
FIG. 4 is an isolated, exploded, perspective view of the frame of
the apparatus according to the prior art.
FIG. 5 is a front perspective view of one embodiment of an
apparatus according to the prior art.
FIG. 6 is the rear perspective view of the apparatus of FIG. 1.
FIG. 7 is an enlarged view of the region of FIG. 6 depicted with an
"A".
FIG. 8 is a schematic of certain functional elements of an
apparatus according to the prior art, connected to a control
box.
FIG. 9 is a front perspective view of a further embodiment of an
apparatus according to the prior art.
FIG. 10 is the rear perspective view of the apparatus of FIG.
9.
FIG. 11 is a photo of a disposable mixer and cartridge, shown in
isolation, for use in the apparatus of FIG. 5.
FIG. 12 is a photo close-up of the spray head of an apparatus
generally similar to that of FIG. 6.
FIG. 13 is a photo of the apparatus of FIG. 5, connected to a
control box.
FIG. 14 is a schematic of a method of utilizing the apparatus of
FIG. 5 to coat a pipe cutback region.
FIG. 15 is a photo close up of the wireless control pendant of the
prior art.
FIGS. 16A-16F show various views of a control panel for the
apparatus according to the prior art.
FIG. 17 shows a cutback region of a welded pipe to be coated by the
apparatus of FIG. 1.
FIG. 18 shows a cutback region of a welded pipe with dressing to be
coated the apparatus of FIG. 1.
FIG. 19 shows an apparatus according to FIG. 1 strapped to the
welded pipe according to FIG. 18.
FIG. 20A shows an apparatus according to FIG. 1 strapped to the
welded pipe according to FIG. 18 and indexed spray patterns.
FIG. 20B shows an apparatus according to FIG. 1 strapped to the
welded pipe according to FIG. 18. and indexed spray positions.
FIG. 21A shows an apparatus according to FIG. 1 fastened to a pipe
with a spray stream tilted relative to a pipe longitudinal
axis.
FIG. 21B shows a perspective view of a portion of the apparatus
according to FIG. 1 with a pivot axis of a spray head perpendicular
to a pipe longitudinal axis.
FIG. 22 shows an apparatus according to FIG. 1 strapped to the
welded pipe according to FIG. 18. and a welding interface.
FIG. 23A shows an apparatus according to FIG. 1 strapped to the
welded pipe according to FIG. 18 and indexed spray patterns.
FIG. 23B shows a table having suggested relative conditions for
flow rate and spray pressure vs. indexing position.
FIG. 24 shows a longitudinal view of the apparatus according to
FIG. 1 strapped to the welded pipe according to FIG. 18.
FIGS. 25A and 25B show a cartridge refill station according to the
present invention in side front view and top perspective
respectively.
FIG. 26 shows steps in a process of refilling a cartridge using the
cartridge refill station of FIGS. 25A and 25B.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Described is a relatively small, simple, optionally solvent-free,
automated spray apparatus system useful for uniformly coating a
cut-back area around a girth weld with a plural component coating,
such as a two-part polyurethane or epoxy. The apparatus is in the
form of a "bug" which is configured to, and can be mounted on a
standard, or optionally on a custom manufactured, track which is
clamped to the outer coating of a pipe. The apparatus may be
mounted on a single track.
As shown in FIGS. 1-3, apparatus 10 is configured to mount onto,
and rotate around, track 12 which can be clamped to pipe 14
proximal to cutback region 15. Track 12 comprises a rack 16 which
is operably connected to a drive gear 18 on the frame 20 of
apparatus 10. This configuration provides the ability for apparatus
10 to travel in a motorized, controllable manner, around track 12
and thus around the circumference of the pipe 14 in a rack and
pinion arrangement. Apparatus 10 also comprises spray nozzle 32
which is cantilevered over the cutback region 15 of the pipe
14.
FIG. 4 is an isolated, exploded, perspective view of the roller
carriage 44 situated on the frame 20 of apparatus 10 of the present
invention. Frame 20 comprises clamping wall 22 which is spring
biased with springs 24 to an `open` position, and clamped into a
`closed` position utilizing clamping cam handle 26. In the `open`
position, the frame 20 may be mounted onto the track 12 and affixed
thereto by moving lever 26 such that clamping wall 22 moves to a
closed position. Track rollers (28, 30 shown) allow for
displacement of the frame 20 around the track 12.
FIGS. 5-7 show one embodiment of the apparatus of the present
invention, a cartridge-based apparatus. Shown is drive gear 18
connected to servo motor 34 and gear head (not shown), through
drive engagement cam 36. The servo motor 34 is utilized to turn the
drive gear 18, to provide displacement of apparatus 10 around the
circumference of the pipe. Servo motor 34 is controlled by a
programmable controller 40 which can be programmed to provide
automated displacement of apparatus 10 around the circumference of
the pipe in a desired direction and speed. Also shown, though
optional, is drive gear guard 38, which protects the user from
injury due to the turning drive gear 18, and protects the rack and
pinion mechanism of the drive gear 18 and rack from foreign objects
or from spray back of the plural component coating (for example,
epoxy). Electronics protective guard 42 can be a plastic or metal
plate which protects the key electronic components of apparatus 10,
such as the controller 40, from damage from foreign objects or
plural component coating spray back. It would be readily understood
to a person of skill in the art that it would be desirable to
prevent plural component coating from adhering to the drive gear
18, the rack, or the electronic components of apparatus 10.
Apparatus 10 also has carriage 46 configured to receive cartridges
48, 50. Cartridges 48, 50 may be two separate cartridges, each
containing one of the plural components of the coating spray, or,
as shown, may be a single cartridge having two segregated bodies
each containing one of the plural components of the coating spray.
As shown, and its most common embodiment, apparatus 10 is
configured to apply a coating spray having two components, however,
it would be understood to a person of skill in the art that if a
plural component coating spray having more than two components was
desired, the cartridge carriage 46 could easily be configured to
receive more than two cartridges, or alternatively, a single
cartridge having more than two segregated bodies each containing
one of the plural components of the coating spray. Cartridge
pistons 52, 54 are configured to enter cartridges 48, 50, and are
connected to cartridge gun 56, which is pneumatically or
electrically actuated and displaces cartridge pistons 52, 54,
thereby displacing the components contained in the cartridge 48, 50
through cartridge nozzles 58, 60. When cartridge pistons 52 and 54
are electrically actuated, that mechanism may employ an electric
motor (not shown). The electric motor in conjunction with a screw
or rack and pinion mechanism, may translate the rotational motion
of the electric motor into linear motion of the pistons. In use,
cartridge nozzles 58, 60 are attached to a static mixer having
mixing area 130, which is in turn, optionally through a hose 134,
attached to spray nozzle 32, at hose adapter 62.
The actuation of cartridge gun 56 is electronically controlled
through controller 40, programmable, and is coordinated with the
movement of apparatus 10 around the pipe 14 and the movement of the
spray head 64 relative to the frame 20.
The ratio of components displaced out of the cartridge nozzles 58,
60 can be controlled through the difference of diameter of the
bodies of the cartridges 48, 50, or through a difference in the
displacement speed of cartridge pistons 52, 54.
In certain embodiments, the rate at which the components are
delivered to the nozzle is measured by a linear position sensor 61,
attached to cartridge gun 56. This sensor may be in the form of a
rotary potentiometer, linear potentiometer or non-contact type
sensor such as a magnetic potentiometer or optical distance
transducer.
In certain embodiments, the static mixer 130 and hose 134 which
connects the static mixer 130 to the spray nozzle 32 are disposable
components, reducing the requirement for flushing hoses and
solvents. In certain embodiments, the cartridges 48, 50 are
pre-loaded with components and disposable. For example, the
cartridges 48, 50 can be pre-loaded with the desired amount of
components to coat one cut back region, and can be replaced for
each cut-back region being coated. In certain embodiments, the
cartridges 48, 50 are a Sulzer DP 1L cartridge (Sulzer,
Switzerland) and the static mixer 130 is a Sulzer DP static
mixer/flex hose assembly.
In other embodiments, the cartridges are refillable from a
low-pressure bulk supply of component. Such re-filling can be done
between jobs, or it can be done in a continuous manner while the
apparatus is in use. In these embodiments, the cartridges may be
re-utilized. In such embodiments, the cartridges are configured to
receive low pressure component lines (not shown) from a plural
component coating spray delivery system (not shown) which may, for
example, be a continuous delivery system, with each cartridge
receiving, through its own component inlet, a different component
of the plural component coating. A valve can be used to control the
flow of components through the continuous component inlets. In some
embodiments, the low-pressure flow of component is continuous, in
other embodiments, the low-pressure flow of component is
automatically controlled, while in use, based on the amount of
component left in the cartridge. In such embodiments, the component
delivery system is attached to the apparatus through low pressure
conduits while the apparatus is in use. In other embodiments, the
low-pressure flow of component is controlled by the user, for
example, by re-filling the cartridges between coating jobs. For
example, in some embodiments, the cartridge is re-filled between
coating jobs, with a low-pressure flow of component, while the user
replaces the disposable mixer and nozzle. In such embodiments, in
some exemplifications, the apparatus is attached to the component
delivery system (through low pressure conduits) while the apparatus
is not in use, for example, between coating jobs.
Apparatus 10 also has sliding arm 66 comprising three slidable
shafts 68, 70, 72 each covered by protective bellows 74, 76, 78,
respectively. Spray head 64 is connected to the distal end of
sliding arm 66 and thus cantilevered over the cutback region 15. It
would be appreciated that although three slidable shafts 68, 70,
and 72 are shown, any configuration of slidable elements could
comprise sliding arm 66. Sliding arm 66 can slide relative to the
frame 20 and is displaced by a non-captive stepper motor 80 and
lead screw 82 controlled by controller 40 through a multi-channel
pneumatic valve body and regulation/velocity control.
Apparatus 10 has a carrying handle 84 which is adaptable for a
hoist ring. However, due to its size and weight, apparatus 10 can
easily be carried by one user utilizing the carrying handle 84.
The height and position of spray head 64 is adjustable by affixing
it at one of spray head attachment points 86. The spray angle can
also be adjusted by rotating the spray head 64 relative to the arm
66. Spray head 64 comprises spray nozzle 32 operatively connected
to hose adapter 62, and housed in nozzle cradle and quick change
adapter 88 for rapidly changing the spray nozzle 32 when required.
Spray head 64 optionally, and as shown, also comprises laser
alignment module 90 which provides visual identification to the
operator of the central target of the spray pattern and facilitates
quick alignment of the apparatus during set up to a location on the
pipe, typically by aligning the laser "dot" emitted from the laser
alignment module 90 to the weld bead at the center of the field
joint, and air atomization input adapter 92 which provides
pressurized air to the spray nozzle 32. Providing pressurized air
through air hose 63 to the spray nozzle 32 allows the pressure of
the components to remain low as they are displaced from cartridges
48, 50 to the spray nozzle 32, while still having sufficient
pressure to provide a fine spray as the components are released
from spray nozzle 32 onto the pipe to be coated.
Also shown in FIGS. 5 and 6 is spray shield 94, which protects the
body of apparatus 10, as well as the track 12, from spray back of
the coating spray when in use.
Apparatus 10 comprises proximity sensors 96, 97, which are
inductive type proximity sensors with both safety and accuracy
function. The proximity sensors 96, 97 are able to detect when the
sliding arm 66 has reached the end of its lateral travel in both
directions. The proximity sensors 96, 97 are utilized to stop
movement, and prevent unwanted forces from developing in the
powertrain and/or drivetrain of the linear stepper motor. For
accuracy, the front proximity sensor 96 is used in a homing
procedure to detect the "home" position of the lateral slide of the
arm--when the arm is fully unextended, the front proximity sensor
96 sets the absolute position of the axis as zero in the
controller, then indexes all future positions to this "home"
position. As would be understood by a person of skill in the art,
this function could equally be provided by rear proximity sensor
97.
Apparatus 10 also comprises umbilical electrical connector 100
which provides an electrical and electronic connection from
apparatus 10 controller 40 to an external power source (not shown),
and/or an external user interface (not shown) or external processor
(not shown). Umbilical electrical connector 100 also provides power
to drive the servo motor 34, and for the displacement of the
sliding arm 66 and/or the cartridge gun body 56/cartridge piston 54
in embodiments where those components are electrically driven. In
embodiments where the displacement of the sliding arm 66 and/or the
cartridge gun body 56/cartridge piston 54 is pneumatic, apparatus
10 also comprises air quick connect 98 which allows for easy
connection of a pressurized air hose (not shown).
In certain embodiments, and as shown in FIGS. 5-7, apparatus 10
weighs less than 50 lbs, preferably less than 34 lbs, and is thus
easily transportable by one person. Track 12 as shown in FIGS. 1
and 2 weighs about 35 lbs and is therefore also easily
transportable by one person.
In certain embodiments, and as shown in part in FIGS. 5-7 and shown
schematically in FIG. 8, the umbilical electrical connector 100 is
connected to a control box 102 which provides 5 amp, 240 V power
from a power source 104, and compressed air at 90 psi<15 SCFM
from compressed air source 106 to controller 40. The controller
controls servo motor 34, cartridge gun body 56 and stepper motor
80, providing both power and, where appropriate, compressed air,
and controls and receives information from proximity sensor 96 and
linear position sensor 61. The control box 102 can be controlled,
and programmed, by a user using wireless control pendant 108 which
is wirelessly connected to the control box 102. Typically, the
control box 102 weighs about 50 lbs, though this weight may be
brought down in further iterations of the control box; the
umbilical cable (not shown) which connects the control box 102 to
apparatus 10 through air quick connect 98 and umbilical electrical
connector 100 typically weighs about 15 lbs.
In certain embodiments, and as shown in FIGS. 16A-16F, the control
box 102 is preconfigured into a field robust rack 103 that includes
all components for managing electrical safety, communications,
digital controls, programming and air preparation. Programming and
operation is managed through an operator Human Machine Interface
(HMI) 154. Critical operator interface buttons and signals are
available on the front face 156 of the control panel. The enclosure
is environmentally protected and controlled with an integral air
conditioning unit 158. The supply compressed air is conditioned to
remove water mist and particulates with filters 160 and
dehumidified with a membrane air drier 162. The air pressure is
regulated with a regulator 164 and preheated to a specific supply
temperature by a compressed air heater 166. The final temperature
of the air is measured with a temperature sensor 167. The umbilical
cable air quick connect 98 and electrical connector 100 connect to
standard interfaces 168 and 152 respectively.
A further embodiment of the apparatus is shown in FIGS. 9 and 10,
with like parts labelled similarly to the apparatus of FIGS. 5-7.
Apparatus 10 differs from that of FIGS. 5-7 in that it is
configured for continuous delivery, rather than cartridge-based
delivery of the plural components of the coating spray. Continuous
delivery plural component systems are generally fully contained,
commercially available, systems (available for example, from GRACO,
AIRTECH, BINKS or WIWA) that include fluid component preheating and
storage, component pressurization, component mixing and final
delivery, and optionally management of unused components return to
storage. These systems may also include, often as a separate
system, a tertiary component (solvent) management that is used to
clean out the passageways of the system. In all notable
commercially available systems, the principal operating power
driving the component delivery is derived from compressed air. The
compressed air drives proportioned hydraulic rams to pressurize the
components to high pressures and in the correct ratio.
Similarly, to the apparatus of FIGS. 5-7, apparatus 10 is
configured to mount onto, and rotate around, track 12 which can be
clamped to pipe 14 proximal to cutback region 15. Apparatus 10 is
able to travel in a motorized, controllable manner, around track 12
and thus around the circumference of the pipe 14 in a Vack and
pinion` arrangement. Drive gear 18 connected to servo motor 34 and
gear head (not shown), through drive engagement cam 36. The servo
motor 34 is utilized to turn the drive gear 18, to provide
displacement of apparatus 10 around the circumference of the pipe.
Servo motor 34 is controlled by a programmable controller 40 which
can be programmed to provide automated displacement of apparatus 10
around the circumference of the pipe in a desired direction and
speed. Also shown, though optional, is drive gear guard 38, which
protects the user from injury due to the turning drive gear 18, and
protects the rack and pinion mechanism of the drive gear 18 and
rack from foreign objects or from spray back of the plural
component coating (for example, epoxy). Electronics protective
guard 42 can be a plastic or metal plate which protects the key
electronic components of apparatus 10, such as the controller 40,
from damage from foreign objects or plural component coating spray
back. It would be readily understood to a person of skill in the
art that it would be desirable to prevent plural component coating
from adhering to the drive gear 18, the rack, or the electronic
components of apparatus 10.
Unlike the apparatus of FIGS. 5-7, the apparatus of FIGS. 9 and 10
does not have a cartridge carriage configured to receive
cartridges. Instead, it is configured to be connected to
off-the-shelf continuous delivery plural component coating spray
systems. Continuous delivery plural component coating systems are
available from various venders, such as GRACO, AIRTECH, BINKS and
WIWA, and typically provide high pressure two component
epoxies.
Thus, the apparatus of FIGS. 9 and 10 comprises continuous delivery
component inlets 110, 112, which are configured to receive high
pressure component lines from the plural component coating spray
continuous delivery systems (not shown), with each continuous
component inlet 110, 112, receiving a different component of the
plural component coating. Quick release handle 114 allows for rapid
connection and separation of the high-pressure component lines to
apparatus 10. A valve 116, which may be hydraulic, electric, or, as
shown, pneumatic, controls the flow of the components from
component inlets 110, 112 to optionally disposable mixer 118,
through mixer outlet 120 and into a high pressure, optionally
disposable, tube (not shown) which is connected to spray inlet 122
which is, in turn, operatively connected to spray nozzle 124. One
advantage of apparatus 10 over other plural component coating spray
continuous delivery systems may be the size and weldability of the
present apparatus 10, which is much lighter, easily carried and
attached to a pipe by one user, and thus safer to use. A second
advantage, however, is that in certain optional embodiments, all
parts of the apparatus through which flow mixed components are
disposable. Thus, all parts of the apparatus that, in a traditional
continuous delivery system, would require significant cleaning,
flushing, and solvent use, can be disposable and easily user
replaced. Even if non-disposable components are used, they are
easily removed from apparatus 10, for cleaning and flushing. This
is much more convenient, and can be more environmentally friendly,
than flushing plural component coating out of apparatus parts using
(often toxic) solvents in the field.
As would be understood by a person of skill in the art, the
apparatus of FIGS. 9-10 could still be cleaned and flushed in a
traditional manner, by releasing the high pressure component lines
(not shown) connected to the plural component coating spray
continuous delivery systems (not shown) utilizing quick release
handle 114, and replacing them with high pressure cleaning lines
(not shown) configured to release solvent into apparatus 10.
The actuation of actuator 116 is electronically controlled through
controller 40, programmable, and is coordinated with the movement
of apparatus 10 around the pipe 14 and the movement of the spray
nozzle 124 relative to the frame 20.
The ratio of components displaced can be controlled through use of
different pressure lines to apparatus 10, or through having a
separate actuator 116 for each high-pressure component line.
Although not shown in FIGS. 9 and 10, it would be appreciated that
the apparatus may also have an adjustable spray head, and multiple
spray head attachment points, similar to that of the apparatus of
FIGS. 5-7.
Apparatus 10 has a carrying handle 84 which is adaptable for a
hoist ring. However, due to its size and weight, apparatus 10 can
easily be carried by one user utilizing the carrying handle 84.
FIG. 11 shows a photograph of cartridge 48, 50 in isolation, for
use in the apparatus of FIGS. 5-7. Cartridge 48, 50 is mounted into
cartridge carriage 46 as shown in FIGS. 5-7. As shown, cartridge 48
and cartridge 50 are actually housed in a single, plastic,
bicylinder; metal or other materials may also be used, two separate
cartridges may also be used. As shown, cartridge 48 has a larger
diameter than cartridge 50, and contains (as the component) an
epoxy, whereas cartridge 50 contains (as the component) an
associated curing agent.
FIG. 11 also shows static mixer 126 in isolation, for use in the
apparatus of FIGS. 5-7. Static mixer 126 has compound inlet 128 for
connection to cartridge nozzle 58, 60, a mixing area 130 which
mixes the two components together, and hose 134 for transporting
the mixed components to the spray nozzle 32. The mixer 126 shown in
FIG. 11 is slightly different than that which would be used with
the apparatus of FIGS. 5-7, in that the mixer 126 comprises a
built-in spray nozzle 132 and air atomization input adapter 92.
Accordingly, the end of the mixer 126 can simply be clipped into
the arm of the apparatus, utilizing quick change adapter 88. The
advantage of utilizing an "all in one" mixer 126, comprising a
built-in spray nozzle 132, like the one shown in FIG. 11, is that
the entire assembly is disposable, which eliminates the need for
cleaning spray nozzle 32. In alternative embodiments, such as that
shown in FIG. 5-7, spray nozzle 32 is a separate element, which may
be removed for cleaning by utilizing quick change adapter 88. As
would be appreciated, the apparatus of FIG. 5-7 is configured so
that a separate component spray nozzle 32 such as that depicted in
FIGS. 5-7 can be interchanged with a built-in component spray
nozzle 132 such as that depicted in FIG. 11.
FIG. 12 is a photograph close-up of the spray head 64 of a further
embodiment of apparatus 10. FIG. 12 clearly shows sliding arm 66
comprising three slidable shafts 68, 70, 72 each covered by
protective bellows 74, 76, 78, respectively. Spray head 64 is
connected to the distal end of sliding arm 66. Height and position
of spray head 64 is adjustable by affixing it at one of spray head
attachment points 86. The spray angle can also be adjusted by
rotating the spray head 64 relative to the arm 66. Spray head 64
comprises spray nozzle 32 operatively connected to hose adapter 62,
which is in turn connected to component hose 134. Spray head 64
comprises air atomization input adapter 92 which provides
pressurized air to the spray nozzle 32. Also shown is spray shield
94, which protects the body of apparatus 10, as well as the track
12, from spray back of the coating spray when in use.
FIG. 13 is a photo showing apparatus 10 connected to control box
102 by umbilical cable 136, which provides electrical power,
compressed air, and a communications conduit. Wireless control
pendant 108 and track 12 are also shown.
FIG. 14 is a schematic briefly describing the use of apparatus 10
to coat a cutback region. First, the track ring is positioned and
mounted onto the outer coating layer of a pipe, proximal to the
cutback region. The track ring is clamped in place. Apparatus 10 is
mounted to the track ring so that the drive gear 18 is engaged onto
rack 16, and locked in place with clamping cam handle 26. The servo
motor 34 is engaged to "jog" apparatus 10 to an accessible location
on the side of the pipe. The stepper motor 80 is engaged to center
the end of arm 66 on the weld bead situated in the middle of the
cutback region. The user confirms the position is set by pressing
the "zero" position button 138 on the wireless control pendant 108,
shown also at FIG. 15. A pre-heated component cartridge 48, 50 is
installed in cartridge carriage 46. The component inlet 128 of
static mixer assembly 126 is affixed to the end of the cartridge
48, 50 at cartridge nozzles 58, 60. The other end of static mixer
assembly 126, containing built-in spray nozzle 132, is fixed into
quick change adapter 88 and a compressed air source is affixed to
air atomization input adapter 92. The static mixer assembly and
nozzle is primed by pressing the "prime" button 140 on the wireless
control pendant 108, which activates the cartridge gun body 56 to
displace pistons 52, 54 to displace the two components out of the
cartridge and into the mixer 126. The mixed plural component
mixture is displaced through nozzle 124 and collected in a
receptacle. The apparatus is now primed and ready to coat the pipe.
The user pushes the "run" button 142 on the wireless control
pendant 108, which initiates the spray cycle. Apparatus 10
progresses through a programmed spray cycle, rotating around the
pipe on track 12 and moving arm 66 (and, as a result, spray nozzle
124) laterally to coat the entirety of the cutback region 15. The
movement of the apparatus can be programmed in a wide variety of
ways; in a preferred embodiment, the apparatus is repeatedly
rotated circumferentially around the pipe, with lateral steps of
the arm at each rotation. In a preferred embodiment, the spraying
occurs continually, though pulse spraying or pauses in the spraying
can also occur. As can be appreciated, servo motor 34, cartridge
gun body 56, and/or stepper motor 80 may be electronically
controlled in a programmable or pre-programmed manner through an
on-board computer or through a computer at the control box 102. A
user selects the parameters (pipe diameter, desired thickness of
coating, and type of coating, for example) on a user interface (for
example, control pendant 108) then initiate the start of the
coating process; apparatus 10 would then automatically rotate and
arm 66 would laterally displace appropriately, while at the same
time the main controller would activate the cartridge gun body 56
for the desired application of coating. As shown in FIG. 15,
Control pendant 108 also has controls for manual lateral
displacement of the arm (out, 148, in, 150) and rotational
displacement around the pipe (clockwise 140, counterclockwise 152).
By pressing the "shift" button (156), the second function of the
buttons can be accessed, with button 140 also used to prime the
system, button 152 used to purge the system, and button 148 used to
retract the cylinder. A large, easy to access emergency stop button
158 is also provided.
Once the cutback region 15 has been sprayed in its entirety,
apparatus 10 returns automatically to its start position relative
to the pipe, and the user can remove the now depleted cartridge 48,
50 and the mixer 126; in the case of disposable cartridge 48, 50
and/or mixer 126, disposing of them; in the case of a re-usable
cartridge 48, 50 and/or mixer 126, placing them in a storage
location for cleaning. The user can then unlock apparatus 10 from
the track 12 by disengaging clamping cam handle 26, and remove
apparatus 10 from the pipe. The track 12 can also be removed from
the pipe and moved to the next cutback region.
As would be understood to a person of skill in the art, an
automated cutback coating apparatus such as that herein described
also has the advantage that it can collect data, such as
confirmation that a coating was properly applied, the protocol it
was applied with, and the type of component (for example, epoxy)
used on the cutback. In this manner, the apparatus can provide
objective, standardized, real time data regarding the integrity of
the cutback region coating. For example, each cartridge could have
a bar code or RFID tag, which would be read by a bar code
reader/RFID reader located on an appropriate position on the
apparatus. Part of the application protocol might require reading
such a bar code before the application of coating can take place.
This would reduce the risk of field substitution of inferior
components, for example. The bar code reading would be sent,
through controller 40 to the control box 102, and confirmation of
an appropriate cartridge would be necessary before a user could
apply the coating to the pipe. Similarly, a bar code or RFID
reading can be taken off the pipe at or proximal to the cutback
region, which would provide a unique identification of the specific
cutback to which the apparatus is applying coating. This
information, as well as confirmation of a successful (i.e. error
free) coating, and the time and date the cutback was coated, the
size of the pipe, the temperature of the coating components when
leaving the reservoir housing (by having a temperature sensor
located proximal to that point, or in the case of heated cartridges
as described further below) can be recorded at the control box 102
or on memory (for example, a removable SD card) right on the
apparatus, for audit or documentary purposes.
It would be understood that, although pneumatic or electrical
driving of circumferential travel and/or lateral arm travel are
shown, these could also be operated through hydraulic means. It
would also be understood that although an external source of
compressed gas and an external electric source are shown, in
certain embodiments, the compressed gas, compressed fluid, and/or
electrical source could be incorporated within the apparatus. For
example, the apparatus may further comprise a battery or capacitor,
which may be rechargeable, for example, a solar panel-charged
battery or capacitor; a canister of compressed air, an electric or
gas driven air compressor, or any other known means. For example, a
disposable or refillable compressed air canister (not shown) can be
connected to the back of cartridge gun body 56 to be used as a
source of energy for compressing the pistons 52, 54 and thus
displacing first coating component and second coating component out
of the cartridges 48, 50.
Accordingly, in certain embodiments, the entire apparatus 10 can be
self-contained, and does not require additional generators, coating
containers, hoses, or connections, making apparatus 10 both more
efficient and less dangerous to use.
For some coating components, it is advantageous to heat the
components before application. Therefore, in certain embodiments,
apparatus frame 20 may also comprise a heating means for heating
the coating components in the reservoir. Alternatively, or in
addition, a plurality of reservoir housings can be stored in a
separate, self-contained, heated container, and pulled out and
affixed to the apparatus frame 20 immediately before
application.
Although not shown, coating systems containing more than two
components may also be used, by providing a cartridge carriage 46
capable of containing more than two cartridges 48, 50. In some
cases, this may require minor modifications to the coating
actuator, for example, additional pistons or alternate displacement
means may be required. In certain embodiments, the individual
pistons (or other displacement means) are housed and a component of
the reservoir housing itself, providing a universal connection with
the coating actuator.
Rotational travel speed of the apparatus may be variable or
constant, and typically may be anywhere from 0-1500 mm/s, depending
on the pipeline application, the coating to be applied, and the
geographic conditions.
In addition to the inventive design concepts disclosed above,
additional features may enhance operation of the machines and/or
systems disclosed.
FIG. 17 shows two pipes joined together by welding and inspection.
Specifically, a first pipe 1710 is joined to a second pipe 1720 by
a weld 1730. Pipes 1710 and 1720 are covered in the factory by
factory insulation 1750 except for a bare portion 1740 of pipes
1710 and 1720 in proximity to weld 1730. Pipe portion 1740
continues to be referred to herein as the cutback region. FIG. 18
again shows the bare cutback region of the pipe between the factory
coating to be coated. About 2 inches at the interface between
factory coating 1750 and the bare pipe 1740 may be dressed to
improve adhesion (e.g., adhesion of any coating sprayed on the
cutback region). The dressing may taper off on both sides toward
the weld and may provide a seal between the dressing and the
factory coating.
FIG. 19 shows the spray apparatus 10 attached to pipe 1720. A spray
stream 1920 flows from spray nozzle 32 in a fan shaped spray
pattern onto weld 1730. As discussed above, spray nozzle 32 of
apparatus 10 may move automatically and/or incrementally back and
forth in a direction parallel the longitudinal axis of pipe 1720.
So slide arm 66, stepper motor 80 and screw 82 function together
with controller 40 to amount to an indexer for indexingly moving
spray nozzle 32 longitudinally in, into and between discrete
positions as show in FIG. 20A. Specifically, indexing may include
not merely an automatic moving from position to position, but also
a stopping for a period at a position (e.g., one of positions 1-9)
before starting again. FIG. 20A shows 9 discrete spray pattern
positions 2010 associated with 9 corresponding discrete spray
nozzle 32 positions. The nine positions are aligned with the
longitudinal axis of the pipe 1710 and the nine spray patterns are
superimposed to showing how the spray patterns would overlap to
cover the surface of the cutback longitudinally at that particular
angular positioning of apparatus 1 (e.g., at 12 o'clock or 1
o'clock looking down the pipe). The combined spray patterns 2010
cover the cutback which includes the dressing right up to the edge
of the factory coating 1750.
For a number of reasons, it may be desirable to apply spray
coatings differently depending on the longitudinal indexing
position (i.e., positions 1-9). For example, at some positions, the
flow rate may be increased or decreased so that more or less spray
material may be applied at that circular/orbital longitudinal
position. For example, in FIG. 20B, less spray may be needed at the
longitudinal position nearest the factory coating where the
dressing is (i.e., spray position 1) than where there is bare pipe
(i.e., such as in position 3) since the dressing can be a partial
coating. Similarly, it may be desirable to apply more coating at
position 5 where weld 1730 is as that position has more surface
area to cover than the bare pipe at position 3. When less spay is
needed, the flow rate through nozzle 32 may be reduced during
spraying at that longitudinal position in order to apply less
coating material. Alternatively, the speed of the position of spray
nozzle 32 might be increased so less time is spent applying
material at a particular longitudinal position and less material is
applied.
It has been discovered that the spray nozzle most uniformly and
precisely distributes spray material and the spray pattern is
most/best defined when spray material supply hose 134 defines a
vertical channel immediately as material enters spray nozzle 32
from hose 134. In other words, the spray pattern is desirable when
spray nozzle 32 is vertically oriented and at least an end portion
of hose 134 is also vertically oriented to deliver spray material
to nozzle 32 in line with nozzle 32. On the other hand, spray
apparatus 10 may also employ a pray head tilt feature (i.e., nozzle
32 tilts with the spray head) in order to most effectively
distribute spray material onto the pipe exterior. FIG. 21A shows a
spray apparatus 10 which has sprayed three different streams of
spray material at three different spray locations. Specifically,
the spray location closest to spray apparatus 10 is sprayed at an
angle that is tilted relative the two other pray material spray
streams. In other words, the two leftmost spray streams of FIG. 21A
are delivered by a spray nozzle that is vertically oriented while
the rightmost spay stream is tilted toward the left. As discussed
above, the ability of spray apparatus 10 to tilt its nozzle would
enable spray apparatus to limit overspray at the edges of where
spray is to be applied. FIG. 21B shows a spray head with a nozzle
32 or air spray tip. Nozzle 32 has a spray axis about which nozzle
32 can pivot or tilt in directions D in order to adjust the angle
of the spray stream relative to the pipe longitudinal axis.
The tilt may be automatically adjusted to an angle theta (i.e.,
angle between a longitudinal center of the flow stream and a
vertical line from pray nozzle 32 and perpendicular to the pipe
longitudinal axis). Automatic or powered movement may be controlled
by a controller (e.g., controller 40). Controller 40 may send a
signal to mechanical movers (e.g., electric solenoids or pneumatic
cylinders). The tilt angle may also be controlled by a mechanical
structure such as a cam and/or cam follower which engages/pivots
the nozzle at a particular position along the longitudinal travel
of the spray head. In one embodiment the mechanical tilter can be a
spring actuated device that triggers at set points in the
longitudinal cross stream travel. In another embodiment the
mechanical tilter could be motorized and provide continuous angle
adjustment across the cross stream (as opposed to mere actuation at
discrete positions). In any case, the tilt of the spray head may be
adjusted with respect to the longitudinal position of the spray
head along cutback region 15.
As mentioned above, spray nozzle 32 is supplied with a flow of
pressurized air. The pressurized air is discharged from spray
nozzle 32 together with the coating material in generally the same
spray direction to disperse the coating material in a particular
spray patter. For a given spray nozzle 32 at a given distance from
the pipe surface, the spray pattern can be modified by adjusting,
modifying, or regulating the pressure of supplied air.
Specifically, increasing the supplied air pressure tends to focus
the spray pattern (more control and/or more defined pattern) and
lowering the pressure tends to loosen the spray pattern (less
control and/or less defined pattern). For example, and as shown in
FIG. 22, in order to avoid over spraying at the interface 2210
between the dressing and the factory coating, it may be desirable
to increase air pressure to increase focus and control of the spray
pattern to reduce overspray. On the other hand, in other
longitudinal positions (e.g., positions 3-7) away from interface
2010, an optimal spray pressure may be used concerned only that a
smooth coat is applied to the bare pipe and/or weld.
FIGS. 23A and 23B show a chart that describes some suggestions for
varying certain parameters (i.e., flow rate and spray pressure) for
each of the nine indexed longitudinal positions described above.
For example, at position 1 where less coating material is needed on
the dressing, but more control is needed to avoid overspray, the
flow rate can be relatively "LOW" compared to a bare pipe position
and the spray pressure can be relatively "HIGH" compared to bare
pipe position. In addition, for example, at position 3 where the
spray pattern only covers bare pipe, both flow rate and nozzle air
pressure can be "NORMAL" (i.e., higher and lower respectively
relative to position 1). Finally, at the weld position 5, flow rate
can be high to cover the additional area of the weld and spray
pressure can be normal because spray pattern focus or definition is
not critical at the weld away from the dressing and factory
coating.
FIG. 24 shows the apparatus 10 installed on a pipe looking down the
longitudinal axis of the pipe. FIG. 24 shows various angular
positions of the apparatus 10. The present invention contemplates a
spray machine that is also capable of adjusting the coating
material flow rate and/or the nozzle air pressure in terms of the
angular position of apparatus 10 as shown in FIG. 24. As apparatus
10 moves around the pipe, spray from the nozzle which is subject to
gravity is applied to the pipe in a different pattern depending on
the position of apparatus 10. In other words, a spray radially
inward from an apparatus position of 3:00 o'clock or 9:00 o'clock
would create a pattern on the pipe slightly lower relative to spray
nozzle 32 than the pattern that would be created had the apparatus
10 been at 12:00 o'clock. In addition, spraying of coating material
while spray nozzle 32 is moving relative to the pipe creates a
spray pattern different that when there is no movement or a
different speed movement. Therefore, varying the coating material
flow rate and/or the nozzle air spray pressure relative to either
radial position of apparatus 10 or speed or change of speed of the
spray nozzle can provide additional control of the ultimate
application of coating material on the pipe.
In use, the track 12 is fixed on the pipe. Then the apparatus 10 is
adjusted (calibrated) so that the mid-stroke of the longitudinal
actuator 80, 82, 40 of sliding arm 66 is in line with weld 1730. In
other words, slide arm 66 is set to have equal reach from weld 1730
toward the factory coating 1750 in both longitudinal directions.
Slide arm 66 is also adjusted so that it extends longitudinally in
alignment with the longitudinal axis of pipe 1710, 1720. Spray
nozzle 32 is indexed to one of the 9 positions. The process can
have more or less than 9 positions depending on the size of the
pipe, size of the spray patter, distance between the spray nozzle
and the pipe, etc. Apparatus 10 can then apply coating material
orbitally around the pipe at the particular indexed position and
the particular spray setting (i.e., low or high flow rate vs. index
position, low or high spray pressure vs. index position, low or
high flow rate vs. axial apparatus position, low or high spray
pressure vs. axial apparatus position).
As discussed above, cartridges 48 and 50 are refillable. Cartridges
48, 50 include and input/output valve 2560 through which coating
material may enter cartridge 48, 50 during refill or leave
cartridge 48, 50 during operation of apparatus 10. Cartridge 48, 50
also includes a moving wall or piston 2570. The present invention
contemplates a refill station 2510. Filling station 2510 includes
one or more material storage containers 2520, 2530. Material
storage containers 2520, 2530 include one or more discharge
valve(s) 2540. The discharge valves 2540 may include quick connect
connectors for quick connection to an input/output valve of
cartridge 48. Filling station 2510 also includes a fill actuator
2550. Fill actuator 2550 is a powered (e.g., electric or pneumatic)
actuator with an extension that extend and retracts from a base. A
pneumatically powered actuator may include a piston and cylinder
and an electric actuator may include a motor and screw mechanism.
Extension 2580 is connectible to moving wall 2570 of cartridge 48,
50. Extension 2580 can be connected to moving wall 2570 of
cartridge 48, 50. When extension 2580 is connected to moving wall
2570, fill actuator 2550 can retract extension 2580 relative to
base 2575 so that moving wall 2570 is retracted relative to
cartridge 48, 50 to draw coating material from storage containers
2520, 2530, through discharge valve 2540, through input/output
valve and into cartridge 48, 50 for refill of cartridge 48, 50.
In use, a technician approaches refill station 2510. The technician
connects an empty cartridge 48, 50 to refill station 2510.
Specifically, input/output valve 2560 is quick connected to
discharge valve 2540. That quick connection may or may not
automatically open discharge valve 2540. In addition, extension
2580 is connected to moving wall 2570. Fill actuator 2550 is then
actuated to retract extension 2580 and moving wall 2570 to draw
coating material into respective compartments from fill containers
2520, 2530 in the manner described above. The technician then quick
disconnects input/output valve 2560 from discharge valve 2540 and
valve 2540 may or may not then automatically close. Cartridge 48,
50 may then be reinstalled into apparatus 10 for discharge of its
new contents.
The embodiments of the present disclosure described above are
intended to be examples only. The present disclosure may be
embodied in other specific forms. Alterations, modifications and
variations to the disclosure may be made without departing from the
intended scope of the present disclosure. While the systems,
devices and processes disclosed and shown herein may comprise a
specific number of elements/components, the systems, devices and
assemblies could be modified to include additional or fewer of such
elements/components. For example, while any of the
elements/components disclosed may be referenced as being singular,
the embodiments disclosed herein could be modified to include a
plurality of such elements/components. Selected features from one
or more of the above-described embodiments may be combined to
create alternative embodiments not explicitly described. All values
and sub-range s within disclosed ranges are also disclosed. The
subject matter described herein intends to cover and embrace all
suitable changes in technology. All references mentioned are hereby
incorporated by reference in their entirety.
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